The present invention relates to a flush valve for toilets, and more specifically to a converter or adapter for changing a single flush valve into a dual flush valve.
In order to prevent the unnecessary of use of water when flushing a toilet, a number of different dual valve systems have been designed which enable the toilet to be flushed using either a large amount or a reduced amount of water as desired.
An early example of a dual valve system of this type is disclosed in Rath U.S. Pat. No. 1,474,288. In this construction, a pair of flapper valves are positioned at different heights on a unitary tubular valve housing. Each valve is independently operated and enables an individual to utilize either a large amount or a reduced amount of water when flushing the toilet.
Other examples of dual valve systems are disclosed in Eastman U.S. Pat. No. 3,795,016; Contreras U.S. Pat. No. 4,042,982; Cameron U.S. Pat. No. 4,175,295 and Bliss U.S. Pat. No. 6,178,567B1. In each of these patents, a pair of flapper valves are disposed at different heights on a valve housing. Each of the flapper valves is connected to a pivotable handle by a chain extending from the valve to an attachment point on the handle or to a lever extending from the handle. In order to control the volume of water utilized when flushing the toilet, the handle is rotated in a first direction to open the higher flapper valve to provide the desired amount of water. To open the lower flapper valve, the handle is either rotated in the opposite direction or rotated further in the first direction to open the lower valve and use an increased amount of water when flushing the toilet.
While each of the above-referenced patents illustrates a useful manner of controlling the amount of water utilized when flushing a toilet, in each of the above patents, the dual valve system is comprised of a single structure on which the pair of flapper valves are disposed. As a result, when incorporating one of these dual valve systems into an existing toilet, the single valve system already present within the toilet must be completely removed in order to insert the particular dual valve system. The single valve system is then discarded, resulting in a significant waste of material and money. Furthermore, should the valve housing for the dual valve system ever become damaged, the entire valve housing must be removed and replaced which increases the expense of utilizing a dual mode valve system, reducing the benefit obtained by the reduction in water consumption.
Therefore, it is desirable to develop a converter or adapter for a conventional single valve flush system capable of converting the single valve system into a dual valve flush system. Such a converter should be easily attachable to the flush tank for the toilet and to the existing single valve system.
It is an object of the invention to provide an adapter for converting a single valve flush system into a dual valve flush system incorporating the conventional single valve system.
It is another object of the invention to provide an adapter that is easily attachable to the existing single flush system and to the flush tank for the toilet.
It is still another object of the invention to provide an adapter that has a simple construction and is inexpensive to manufacture.
It is still a further object of the present invention to provide an adapter which can be configured for mounting to either a side wall or a front wall of the flush tank to accommodate various configurations for the particular single valve system located within the tank.
The present invention is an adapter for a single valve flush system utilized to convert the single valve system into a dual mode valve system. The adapter includes a first tubular section having an open upper end securable to the bottom of the single valve system and a closed lower end, and a second tubular section having an open upper end and an open lower end attachable to the flush tank. The second tubular may conveniently comprise one type of existing flapper valve commonly used. The first section and second section are connected by a hollow channel extending between the lower end of the first section and the upper end of the second section such that the upper end of the second section is generally at the same height as the lower end of the first section.
The adapter also includes a flapper valve pivotally mounted to the first section and releasably engageable with the upper end of the second section to selectively open and close the upper end of the second section.
When the adapter and the single valve system are secured to one another and to the flush tank, the flapper valves are operated by a pair of handles located on the exterior of the tank and attached to a mounting assembly. The mounting assembly includes a sleeve extending through a wall of the flush tank and enclosing a pair of cylindrical arms that are rotatably contained within a pair of throughbores extending through the sleeve. Opposite the handles, the arms are connected to a pair of levers which are in turn connected to a pair of chains which lead down to the flapper valves. By moving one or the other of the handles, the selected valve can be opened in order to flush the toilet with the desired volume of water.